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Linking partial migration to the breeding grounds

Poslinska, Ewa (2014) BION32 20132
Degree Projects in Biology
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Linking partial migration to the breeding grounds

Partial migration is a behaviour that characterise a single population within which only some individuals migrate. That gives a unique chance for comparison of individuals that leave the breeding grounds during winter and the other individuals that remain the whole year round. This may cause several differences between the individuals that belong to the same population.

The population of partially migratory bird species the White-Throated Dipper Cinclus cinclus, was studied in this project. Based on the ringing recoveries only 10% of the breeding birds were defined as migrants and 90% as residents. Both groups are affected differently in a negative way during winters and they gain... (More)
Linking partial migration to the breeding grounds

Partial migration is a behaviour that characterise a single population within which only some individuals migrate. That gives a unique chance for comparison of individuals that leave the breeding grounds during winter and the other individuals that remain the whole year round. This may cause several differences between the individuals that belong to the same population.

The population of partially migratory bird species the White-Throated Dipper Cinclus cinclus, was studied in this project. Based on the ringing recoveries only 10% of the breeding birds were defined as migrants and 90% as residents. Both groups are affected differently in a negative way during winters and they gain different advantages by the one of the two wintering strategies.

The migratory status is not related to the age nor the sex of the bird. The number of migrants neither depended on the winter conditions at the breeding grounds. What indicates that this behaviour is rather inherited genetically and since it is not condition dependent, it can be defined as obligatory partial migration. Even though migrants fly long distances, I found an indication of their wings to be slightly shorter than residents’ wings. That may suggest that larger individuals tend to remain on the breeding grounds all year round.

A big impact of an individual based trigger for migration among White-Throated Dippers in Southern Norway
Almost all of the migrants flew in southeast direction. Most of the recoveries were reported from Danmark which is the closest wintering area that most probably provide suitable wintering conditions. Interestingly, the number of migrants was observed to increase through the study period. Even though the direction was uniform, the distances differed.

In the case of this population it has been reported that the population size fluctuates together with the changing environmental conditions. After every harsh winter the population crashes and most of the birds that are breeding the following breeding season are migrants. That indicates that the overall population structure depended on the wintering strategy obtained at an individual level, yet it is influencing the entire population.

Advisor: Anna L.K. Nilsson & Jan-Åke Nilsson
Master´s Degree Project 45 credits in Animal Ecology 2014
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Poslinska, Ewa
supervisor
organization
course
BION32 20132
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4648649
date added to LUP
2014-09-23 15:17:55
date last changed
2014-09-23 15:17:55
@misc{4648649,
  author       = {Poslinska, Ewa},
  language     = {eng},
  note         = {Student Paper},
  title        = {Linking partial migration to the breeding grounds},
  year         = {2014},
}